diff --git a/src/collapse/collapse.js b/src/collapse/collapse.js
index 7e605b641d..a449cc7e41 100644
--- a/src/collapse/collapse.js
+++ b/src/collapse/collapse.js
@@ -104,6 +104,7 @@ angular.module('ui.bootstrap.collapse', [])
               if ($animateCss) {
                 $animateCss(element, {
                   removeClass: 'in',
+                  easing: 'ease',
                   to: cssTo
                 }).start()['finally'](collapseDone);
               } else {